The Shadow Council

From World of Warcraft's Story section:

The First War

Kil'jaeden, seeking to tighten his hold over the orcs, helped Gul'dan found the Shadow Council, a secretive sect that manipulated the clans and spread the use of warlock magics throughout Draenor. As more and more orcs began to wield warlock magics, the gentle fields and streams of Draenor began to blacken and fade. Over time, the vast prairies the orcs had called home for generations withered away, leaving only red barren soil. The demon energies were slowly killing the world.

The orcs became increasingly aggressive under the secret control of Gul'dan and his Shadow Council. They constructed massive arenas where the orcs honed their warrior skills in trials of combat and death. During this period, a few clan chieftains spoke out against the growing depravity in their race. One such chieftain, Durotan of the Frostwolf clan, warned against the orcs' losing themselves to hate and fury. His words fell on deaf ears, however, as stronger chieftains such as Grom Hellscream of the Warsong clan stepped forward to champion the new age of warfare and dominance.

Kil'jaeden knew that the orc clans were almost ready, but he needed to be certain of their ultimate loyalty. In secret, he had the Shadow Council summon Mannoroth the Destructor, the living vessel of destruction and rage. Gul'dan called the clan chieftains together and convinced them that drinking Mannoroth's raging blood would make them utterly invincible. Led by Grom Hellscream, all the clan chiefs except Durotan drank and thereby sealed their fates as slaves to the Burning Legion. Empowered by Mannoroth's rage, the chieftains unwittingly extended this subjugation to their unsuspecting brethren.

Through a joint effort, Medivh and the warlocks of the Shadow Council opened the dimensional gateway known as the Dark Portal. This portal bridged the distance between Azeroth and Draenor, and it was large enough that armies might pass through it. Gul'dan dispatched orc scouts through the portal to survey the lands which they would conquer. The returning scouts assured the Shadow Council that the world of Azeroth was ripe for the taking.

The Second War

• King Llane was assassinated by one of the Shadow Council's finest killers: the half-orc, Garona.

Beyond the Third War

Even in the aftermath of the second invasion of the Burning Legion, there still remained servants of the Shadow Counsel. They now call themselves Jaedenar, in homage to the demon Kil'jaeden. They reside in Felwood and include members of all races.